The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingVehicle speed sensor "A"
description
The speed sensor detects the wheel speed and sends the appropriate signals to
the skid control ecu.
The skid control ecu converts these wheel speed signals into a 4-pulse signal
and outputs it to the ecm
via the combination meter. The ecm determines the vehicle speed based o ...
Gauges and meters
The units used on the speedometer may differ depending on the target
region.
Tachometer
Displays the engine speed in revolutions per minute
Speedometer
Displays the vehicle speed
Fuel gauge
Displays the quantity of fuel remaining in the tank
Shift position and shift ran ...
Test mode procedure
Hint:
By switching the skid control ecu from normal mode to
test mode, abnormality detection sensitivity is enhanced
and troubleshooting can be conducted efficiently.
Perform a sensor check in test mode after the speed
sensor or sensor rotor has been repaired or replaced.
If the igniti ...